Servers by jDrones

SingleCopter & CoaxCopter Support

(MadD MacKx) #21

@rmackay9 @Leonardthall @Randy_Hills

Alright, I’ve finally had a free couple hours to sit down and play around a bit with the new coax firmware.

Here are some links to a quick video of my bench test and also the bin file of that test.

As for the results most everything can be seen and heard in the video.
-servos work but the responses seem VERY sluggish and slow to respond to the inputs requested (but im chalking that to the fact that the test bench is fixed and the imu is not sensing the any corresponding movement from the fc itself)

-Servos are buzzing as well (which you can hear in the video) they are Emax ES08MAII analog servos but if i change the servos to 50Hz they get EXTREMELY warm very quick so I have since left them at 250Hz

-My motors as you can see in the video respond to all inputs but they “do not” spool up till half throttle and they seem to have very little throttle control as far as actual flight might be concerned. Having the motors shut off at half throttle has so far stopped me from actually mounting the props and test hovering my prototype.

-Im sure i’m missing a lot of info but i think the video and the log will answer most every question…but whatever I missed I’ll be glad to respond too.

Also if there is anything else I can do to help get this firmware up and fully functioning I would be glad to pitch in with whatever I can.


MadD MacKx

One last thing, where can I find the setting for turning off the crash detection?? Edit:I found the setting it in the param tree

(MadD MacKx) #22

@rmackay9 @Leonardthall @Randy_Hills

Hers a link to a longer video showing a lot more and also the bin log file for that test.



Thanks again guys for taking the time to review my tests :smile:

MadD MacKx

Edit: skip past the first minute of the video…I forgot that I had disconnected the receiver lol :yum:

(Jacko) #23

@rmackay9 @Leonardthall @Randy_Hills

Great test rig there Mad Mac makes things so much easier with everything in a controlled set up.
Those videos characterise exactly what I see with the Single Copter particularly with regard to the servos being sluggish and the buzzing.

With the servos like that, it’s not going to fly at this point.

I’m trying to grope my way through the code on GitHub to see if I can tackle these kinds of issues, but this level of c++ programming is sadly beyond my abilities.

(Jacko) #24

I belive i may have a solution to the servo buzxing but this will have to wait till weend for a test. A binary build is a major under taking for me I’m afraid.

I wanted to ask. There seems to be zero servo response from yaw changes in the video. Is this correct?

(MadD MacKx) #25


Yes you are correct about seeing no servo movement with yaw input.

I also changed my servos to some cheapo hextronic ones and the buzzing has be seriously reduced. Ill try and get a video posted before the weekend.


(Jacko) #26

@Leonardthall @rmackay9 @maddmackx

I have the same problem with the throttle now as MadD. Motor response is on/off at around half input but no proportional control.

Also noticed I am unable to change out of stabilized mode after I have armed for so can’t auto take off. Pixhawk buzzer gives long tone and refuses to change mode.

@Leonardthall I can post a Data Log can you kindly tell me the log bit mask to set?

Many thanks

(Leonard Hall) #27

Hi Jacko,

Your log mask should be - 192509

Hi maddmackx,
Could you repeat your throttle tests with the I max set to zero for roll, pitch and yaw. I am wondering if the throttle is being increased to give the roll and pitch extra authority.

sorry for the slow reply!!!

(MadD MacKx) #28

Hello @Leonardthall @rmackay9 ,

Just to confirm…what setting exactly should I set to zero? Im assuming its the VEL_XY_IMAX that I should be changing? currently it is set at 1000 cm/s/s

LOL as far as the slow reply is concerned…its not a problem at all. We all have lives outside of this…speaking for myself, I’ve worked full time as a carpenter for the last 17 years…so the code side is well above my expertise… But as far as building, configuring, beta testing and flight testing is concerned that is where I can make my personal contributions…In all honesty…Thank you for taking your own personal time to help me and @Jacko1 …its greatly appreciated :grinning:

Im just excited that Im getting all this help to get this firmware up and running and being given the opportunity to hopefully help contribute to make this frame firmware a selectable downloadable icon within MP.

Whatever I can do to help…just ask :slight_smile:

(Leonard Hall) #29

Hi Maddmackx,
Thanks, I really appreciate that!!!

The parameters I would like you to set to zero is RATE_PIT_IMAX, RATE_RLL_IMAX and RATE_YAW_IMAX. Just set them all to 0.

I just wanted to take the I term buildup out of the equation. If you could do another video and with the dataflash log, that would be great!!

Thanks again,

(MadD MacKx) #30


Thats not a problem at all :slight_smile:. I will get some testing done tomorrow (its the wifes day today :wink: ) and ill post the video and dataflash log. Are there any particular stick inputs you would like me to do in particular?..such as full throtle with yaw and roll ect. or just pretty much repeat what ive done in the other videos?

MadD MacKx

(Jacko) #31

@Leonardthall @rmackay9 @maddmackx

Single Copter Flies!!(but not very well :frowning: )

Here is a video and data flash log of the throttle anomaly on single copter. I term at zero. Flights last around 1 second then I grab it quick!

Log of this flight here…

Graph RCIN 3 against RCOU 5 to see the issue.

Also, I show the loud beeps and refusal to change mode once armed.
Thanks for you help guys.

(Christopher Gehrich) #32

I uploaded the CoaxCopter firmware to the board and it seems that the throttle channels are noisy because my servos buzz and do not hold position when plugged into channel 3 or 4. Are those the correct channels? Motors on 1 and 2, servos on 3 and 4?

(Christopher Gehrich) #33

Hi Jacko,
Did you figure out the servo buzzing?


(Jacko) #34

Hi Frag,

I belive on Coax motor is on CH5 - 6 and servos same as singlecopt on 1234, @maddmackx can you help Frag with the motor and servo CH on your Coax setup?

The servo buzzing is an issue yes but I dont know the code to fix it, I have burnt out servos due this. The PWM oscillates wildly from max to min on the logs.
I will do video and log of the servos for the experts here to look at.

(MadD MacKx) #35


Yes @Jacko1 is correct about the motor order 5 and 6 are the motor outputs. Im trying to standardize the motor setup as top motor clockwise as Output 5 and the lower motor counter clockwise as Output 6. As for the servos I have roll as Output 1 and I have the pitch as Output 2. Also like jacko stated ive also burnt up 2 (correction 4 servos now LOL)

Hopefully that helps

MadD MacKx

(Christopher Gehrich) #36

Thanks @maddmackx and @Jacko1,

I wasn’t really sure that 1 &2 were correct because the disarmed signal for the one servo I connected to output 1 went full left, suggesting a signal of 0 angle or 1100ms? I’m pretty sure that my servo was centered on the fin but I’ll check tonight.

My coax frame is the X01 Project so the motors face each other rather than point away from one another. An interesting twist that may require me to switch motor signals so that the CW/CCW assignment is correct.

(Christopher Gehrich) #37


Any progress on the servo buzzing or updates on motor channel assignment?

(Christopher Gehrich) #38

Ok. I tried loading singlecopter, but the frame will not calibrate any longer. I believe it worked with coaxcopter, but none of the control signal were working on that firmware so I tried single.

Any idea why single won’t allow my pixhawk to calibrate?

(Jacko) #39

Hey @rmackay9 @Leonardthall
Could we just pay you to sort single copter out for us?

I for one have bought everything else for my copter and would not mind (in some ways it’s appropriate) to donate some money to have the code to fly my project with.
Just putting that out there for consideration. :slight_smile:

(Leonard Hall) #40

Hi Jacko,

We will get there. I will have a look over the weekend. The hardest part
for me is not having a frame to test with.

Chat soon,